Java Spring嵌套异常是java.lang.StackOverflowError

Question

我有一些实体类并尝试从数据库获取所有数据，但是我遇到了嵌套异常问题。请参阅下面的详细信息: worker 实体:

   Worker{
        @Id
        private Long id;

        @Transient
        private List<WorkerDepartment> workerDepartments;

        @Transient
        private List<WorkerDepartmentPosition> workerDepartmentPositions;

        @Transient
        private List<WorkerAdjustmentBonus> workerAdjustmentBonus;
    }

WorkerDepartment 实体

    WorkerDepartment{
        @Id
        private Long id;

        @ManyToOne
        @JsonBackReference(value = "worker")
        @JoinColumn(name = "worker_id")
        private worker worker;

    }

WorkerDepartmentPosition 实体

    WorkerDepartmentPosition{
        @Id
        private Long id;

        @Column(name = "worker_id")
        private Long workerId;
    }

worker 奖金

    WorkerBonus{
        @Id
        private Long id;

        @ManyToOne
        @JsonBackReference(value = "worker")
        @JoinColumn(name = "worker_id")
        private worker worker;

        @ManyToOne
        @JoinColumn(name = "payment_id")
        private WorkerPayment employeePayment;

        @Column(name = "bonus")
        private Double bonus;
    }

我尝试获取所有工作人员，响应数据为

{"status":"SUCCESS","data":[have full data],"message":"successfully done"}{"status":"ERROR","message":"Handler dispatch failed; nested exception is java.lang.StackOverflowError"}

请给我建议。

Answer 1

该问题可能来自于例如以下内容的交叉引用: Worker 和 WorkerDepartment。当 Jackson 尝试反序列化您的对象时，它会遍历对象图，一旦访问 WorkerDepartment 属性，它就会返回到 Worker 并一遍又一遍地执行此循环。

由于您已经使用了@JsonBackReference(value = "worker")，您几乎已经解决了问题，但是您需要在另一侧使用@JsonManagedReference:

public class Worker{
    @Id
    private Long id;

    @JsonManagedReference
    private List<WorkerDepartment> workerDepartments;

    @JsonManagedReference
    private List<WorkerDepartmentPosition> workerDepartmentPositions;

    @JsonManagedReference
    private List<WorkerAdjustmentBonus> workerAdjustmentBonus;
}

Baeldung 还提供 a good tutorial对此进行进一步阅读。